Day: March 19, 2016

Sailing – specifically small boats in regattas – is a hobby that requires a lot of skill. Like any hobby, there are devices and electronics to make the hobby easier. For sailing, its tactical sailing compasses and GPS units. Remember, you probably don’t want to sail in a straight line, and that means offloading decades of experience to electronics. Instead of spending hundreds of dollars on a sailing computer, [Brook] thought it would be a better idea to build his own robot sailor from a Raspberry Pi and a Pebble smartwatch.

The sensors required for a sailing computer are par for the course – a Ublox GPS unit, a magnetometer, an acceleratometer, and a gyro. Being used on a sailboat also means there’s an anemometer thrown into the mix. These parts are stuffed into a waterproof polycarbonate field box with a USB power bank battery and a Bluetooth USB dongle.

With the hardware in place, it was time to write the software. The UI for this device is a Pebble smartwatch, which means there was a lot of futzing around with C# and Mono. This device is also a sailing data recorder, meaning [Brook] can integrate this project with VisualSail, a desktop application he wrote a few years ago to create 3D replays of sailing races using GPS data.

The Raspberry Pi Zero contest is presented by Hackaday and Adafruit. Prizes include Raspberry Pi Zeros from Adafruit and gift cards to The Hackaday Store!See All the Entries

MRRF, the Midwest RepRap Festival, is in full swing right now. The venue is packed, attendance is way up this year, and the panorama is impressive:

The 2016 Midwest RepRap Festival. Click to embiggen.

New Printers

MRRF is not really a trade show. Yes, there are companies here (Google is picking up the tab for Chinese food tonight), but this is assuredly a community-based event around open source hardware. That said, Lulzbot is here, SeeMeCNC is hosting, E3D, and Ultimachine are all here. This year, there are a few new printers.

Lulzbot’s Taz 6 – the latest update to their flagship printer made its first public appearance at MRRF this year. A product update from Lulzbot isn’t like a product announcement from a normal company. Lulzbot is using rapid prototyping for manufacturing (!). They can iterate quickly and release two new printers in the time it takes Stratasys to come up with a design. This also means the releases are incremental.

If you’ve ever tried to laser flexible rolls of material you’ll know it can be really annoying to setup in the laser cutter.

Most of the time we use magnets, but then you have to make sure the magnets are clear of the work path — and then you end up wasting extra material… It’d be amazing to have a vacuum table that just sucks down your work piece to keep it in place! As it turns out, it’s not that hard to make!

It’s the first full day of fun here at the Midwest RepRap Festival. This year’s turnout is quite impressive—as I’m writing this, we’re an hour or so in and there are already hundreds of people and a couple of R2D2 units milling about.

The talks will begin in a few hours. This year MRRF has expanded to another building, which should tell you something about the growth of this festival. We are excited to hear [Filip] and [Ladi] give a presentation about Jellybox, a STEM-driven project he started to bring 3D printing into education in a comprehensive and hands-on way. The initial idea was based on [Jean Piaget]’s theory of constructionism. [Piaget] was a clinical psychologist who helped advance the idea that human learning is greatly influenced by connecting a person’s ideas with their experiences.

Building a Jellybox printer is about as easy as it gets, and takes about 4-6 hours depending on your skill level. The laser-cut clear acrylic panels are connected with zip ties that lock around 90° plastic brackets. The back panel even has a etched diagram that shows where all the connectors should go, and the wiring is neat and tidy by design. It’s meant to be easy to tear down so that teachers can use them again and again with middle and high school-aged students. The Jellybox is open-source; both the extruder and the hot end can be swapped out in a flash.

IMade3D offers one- and two-day intensive courses in the DC area that cover building a Jellybox and learning some things about 3D modeling. The kit is included in the price of admission. Jellybox kits will be available in a few weeks, but can be preordered today for $799.

Welcome to the 100th Hacklet! This has been a huge week for Hackaday, as we launched The 2016 Hackaday Prize. We’ve invited you to change the world. Hackers, makers, and engineers have already answered the call, with nearly 200 entered projects! What better way to celebrate our 100th Hacklet than taking a look at a few of these early entrants?

We start with [Patrick Joyce] and Raimi’s Arm – Bionic Arm for Kids. Raimi was born with an arm which ends just below the elbow. She’s still a kid – and growing, which means she will quickly grow out of any prosthetic. This has placed bionic arms out of her reach. [Patrick] saw a plea from Raimi’s father for help. 3D printed arms for the disabled are a thing, but [Patrick] couldn’t find one which fit the bill for Raimi. So he’s set out to design one himself. This will be an open source project which anyone with the proper tools can replicate. [Patrick] has already created several test rigs, and is well on the way to building an arm for Raimi and others!

Next up is [castvee8] who has entered the 2016 Hackaday Prize with Building Simplified Machinery. Over the years, [Castvee8] has built a few 3D printers and CNC machines. These projects always start with buying the same parts over and over: ground rods, linear bearings, stepper motors, drivers, etc. [Castvee8] is trying to build 3D printed machines which use as few of these vitamins as possible, yet are still strong enough to work in wood, plastic, wax, foam, and other light maker-friendly materials. So far the simple, modular components and electronics have led to a mini mill, mini lathe, and a drill press for things like printed circuit boards. Keeping things low-cost will make these tools accessible to everyone.

[Keegan Reilly] entered Everyman’s turbomolecular pump. Vacuum pumps are great, but everyone knows the real fun starts around 10^-7 Torr. Pulling things down this low requires a specialized pump. Two common designs are oil diffusion pumps and Turbomolecular pumps. Oil diffusion is cheap, but not everyone wants a hot vat of oil bubbling away in their vacuum chamber. Turbomolecular pumps are much cleaner, but very expensive. [Keegan] is attempting to design a low-cost version of a turbomolecular pump. He’s trying to use Tesla’s bladeless turbine design rather than the traditional bladed turbines used in commercial pumps. So far tests using a Dremel tool and paper discs have been promising – nothing has exploded yet!

Finally, we have [Samuel Bowman] with Seamless IoT Protocol Translation: Common Ground. Love it or hate it, the Internet of Things is going to be here for a while. Every device seems to speak a different language though . Z-wave, Zigbee, LoRa, WiFi, and a host of other protocols, all on different frequencies. Some are frequency hopping, some use mesh networks. [Samuel] is trying to design one device to translate between any of the emerging standards. Common Ground started as a science fair project connecting MQTT to Phillips Hue devices. Once [Samuel] achieved that goal, he realized how much potential there is in a universal translator box. We’re hoping [Samuel] achieves his goals quickly – it seems like new IoT standards are being introduced every day.

New projects are entering the 2016 Hackaday Prize every hour! You can see the full list right here. That’s it for the 100th Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

What do you do, when you want an ohm? What is an ohm, for that matter? Take a wander over to the textbook definitions, and you’re soon deep in a world of coulombs and parallel infinite planes one meter apart in a vacuum that you probably only half remember from your high school physics class. It’s hard work, this metrology lark.

Of course, you can just order a resistor. A few cents each when you’re buying small quantities or much less when you’re buying a reel of five thousand, and there you have it. An ohm. Only it’s not really an ohm, more like nearly an ohm. Within 1% of an ohm is pretty good, but Vishay or Bourns or whoever don’t have the margins to get philosophical about those infinite planes when you’re only giving them a few cents.

When you REALLY want an ohm, you buy a standard resistor, and you pay a more significant sum. You’re never going to wire one of these up to bias a transistor or drive an LED, instead it’s about as close as it’s possible to get on your bench to the value it says on the box and you can use it for calibration purposes. PPM figures well in excess of the resolution of even superior DMMs sound pretty good to us!

Inside he finds hermetically sealed wire-wound resistors, some oil-filled wire-wound resistors, and the occasional hefty piece of manganin. He also tears down some of the hermetically sealed resistors themselves, finding both wire-wound and foil resistance elements within.

Making revisions to existing PCBs with surface mount components often leads to creative solutions, and this insertion of a switch over a tombstoned resistor is no exception. According to [kubatyszko], “this is an FPGA-based Amiga clone. R15 serves as joint-stereo mixing signal between channels to make it easier on headphone users (Amiga has 4 channels, 2 left and 2 right). Removing R15 makes the stereo 100% ‘original’ with fully independent channels. Didn’t want to make it permanent so I decided to put a switch.”

Whether [kubatyszko] intends it or not, this solution is not going to be permanent without some additional work to mechanically secure the switch. We’ve tried this sort of thing before and it sometimes results in the contact area of the resistor being ripped off the substrate and separated from the rest of the resistor, rendering it useless. However, the creative use of the pads to get some additional functionality out of the board deserves some kudos.

We love creative fixes for board problems but it’s been a really long time since we’ve seen several of them collected in one place. We’d love to hear your favorite tricks so let us know in the comments below.